Modular welding equipment

ABSTRACT

Welding equipment that includes a tooling cart for transferring interchangeable tooling modules to a welding machine. A latch is mounted to the welding machine for latching the tooling cart to the welding machine, and a latch is provided for latching the tooling modules onto the tooling cart. A two-piece tooling cart includes a removable upper section for securing tooling modules thereto and a reusable lower section for use with other tooling modules. A welding method permits operation of a welding machine using a user interface that permits modular programming of at least one operational sequence of welding machine valves and weld operations for a variety of different tooling modules. An operator inputs a new sequence of operations using the user interface rather than having to rewrite ladder logic just to switch over the welding machine to use with a different tooling module.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of U.S. Provisional Application No.60/520,062, filed Nov. 15, 2003, the complete disclosure of which ishereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to welding equipment of the type used inmanufacturing plants for production of welded parts. More particularly,it relates to electric welding machines, such as resistance welders andmetal-inert gas (MIG) welders, and related equipment.

BACKGROUND OF THE INVENTION

It has been a common practice in the welding machine industry to buildwelding machines with custom tooling as an integral part of the weldingmachine. In this practice, especially in connection with resistance andMIG welding machines, each machine is dedicated to the manufacture of aparticular part and is not usable for manufacture of other parts. Theworking area of such a dedicated machine includes an attached assemblyof fixtures and tools specifically made, located and adjusted to producethe parts to which the machine is dedicated. The entire machine, fromheavy frame to built-in precision fixtures is treated as capitalequipment on the financial books of the purchaser. When the partsproduced by the dedicated machine are no longer needed, the entiremachine is generally scrapped.

Previously, there had been a longstanding need in the industry toovercome the disadvantages which accompany the practice of usingdedicated welding machines such as the economic loss from scrapping theentire machine when the tools and fixtures are no longer usable becauseof wear and tear or because of termination of production of the part towhich the machine is dedicated. A general solution to this problem isdisclosed in U.S. Pat. No. 6,512,195 which discloses an electric weldingmachine that has a base operating machine which can accept differenttooling modules so that only the tooling module and not the entirewelding machine can be replaced when switching between different weldingprograms or operations.

In the welding machine of the U.S. Pat. No. 6,512,195 patent, thetooling module can be transferred to and from the base operating machinefrom a module transfer cart, or tooling cart, that is useful intransporting and storing the tooling module when not in use. To connecta particular tooling module to the base operating machine for use inwelding parts, the tooling cart containing the tooling module is wheeledup to the base operating machine. A pair of alignment pins on thetooling cart engage and insert into corresponding alignment sockets onthe base operating machine. This helps insure proper alignment of thecart and base operating machine so that the tooling module can be slidoff the cart and onto the base operating machine. Although thisarrangement provides vertical and lateral alignment of the tooling cartand base operating machine, it still allows for relative movement of thetooling cart toward and away from the base operating machine duringtooling module transfer. Additionally, this arrangement does not provideany means for positively latching the tooling module to the tooling cartto maintain the tooling module in place and prevent the tooling modulefrom shifting on the cart as the tooling cart is moved. When aparticular tooling module is not in use on a base operating machine, itis typically stored on a tooling cart until needed. This enables easytransportation and storage of the tooling module without requiring heavylifting equipment. However, this arrangement does require a dedicatedcart for each tooling module.

When switching between tooling modules, new control programming istypically required for the welding machine. As is known, weldingmachines typically include a programmable logic controller (PLC) that isprogrammed to carry out one or more specific welding sequences in whichthe PLC controls operation of both the welding controller and thevarious solenoid valves used to drive pneumatic cylinders or otheractuators that load, manipulate, weld, and unload a part. Programming ofthe PLC has typically been done using ladder logic, with a separate setof ladder logic being written and loaded into the PLC for each differenttooling module used.

It is a general object of this invention to improve upon some of thefeatures of the modular welding machines discussed above.

SUMMARY OF THE INVENTION

In accordance with one aspect of this invention, there is providedmodular welding equipment that comprises (i) a welding machine having abase operating machine and a tooling module supported by the baseoperating machine, (ii) a tooling cart engageable with the weldingmachine, and (iii) a tooling cart latch that includes a first latchmember on the base operating machine and a second latch member on thetooling cart. The tooling cart can be used to transport one of a numberof different tooling modules to and from the base operating machine.During loading and unloading of a tooling module on and off the baseoperating machine, the tooling cart can be latched to the base operatingmachine by engagement of the latch members. In this way, relativemovement between the tooling cart and base operating machine isinhibited during loading and unloading of the tooling module.

In accordance with another aspect of the invention, there is provided atooling cart for use with a tooling module, wherein a tooling modulelatch is provided to secure the tooling module on the cart duringtransportation and storage of the tooling module. The tooling modulelatch preferably is designed so that the tooling module can only beunlatched when the tooling cart is connected in position to the baseoperating machine.

According to another aspect of the present invention, a welding toolingcart is provided which includes a reusable lower section having a baseand wheels along with a separate, upper section that includes a framefor supporting the tooling module. The lower section includes aplurality of locators and the upper section aligns with and fits overthe locators. Then, when a particular tooling module is not currently inuse, it can be stored on the upper section of the cart which is removedfrom the wheeled base so that the lower section can be re-used withanother upper section and tooling module.

According to yet another aspect of this invention, there is provided amethod of operating a welding machine using a user interface thatpermits modular programming of one or more operational sequences ofwelding machine valves and weld operations for a variety of differenttooling modules. The method facilitates switching over to a differenttooling module wherein an operator inputs a new sequence of operationsusing the user interface rather than rewriting ladder logic.

A complete understanding of this invention may be obtained from thedetailed description that follows taken with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of welding equipment including a toolingcart for loading a tooling module into a welding machine, according toan exemplary embodiment of this invention;

FIG. 2 is a top plan view of the welding machine of FIG. 1;

FIGS. 3 through 5 are top plan views illustrating a portion of thetooling cart being engaged with the welding machine of FIG. 1 via alatch;

FIGS. 6 and 7 are top plan views illustrating the portion of the toolingcart being disengaged from the welding machine of FIG. 1;

FIG. 8 is a front perspective view of the latch of FIGS. 3 through 5;

FIG. 9 is a front view of the latch of FIGS. 3 through 5;

FIG. 10 is an exploded perspective view of a two-piece tooling cartaccording to another exemplary embodiment of the present invention;

FIG. 11 is an enlarged top plan view of a portion of the tooling cart ofFIG. 10; and

FIG. 12 depicts an exemplary screen display for use in inputting weldingsequences into the welding machine of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The description that follows will set forth the best mode for carryingout the invention by describing illustrative embodiments of theinventive modular welding machine as presently contemplated. Thisinvention is especially adapted for use with electric welding machinesof all types, but can be used in conjunction with other types ofwelders. This disclosure relates to various improvements to the modularwelding machine disclosed in U.S. Pat. No. 6,512,195, which is assignedto the assignee hereof and which is incorporated by reference herein inits entirety. It will be appreciated as the description proceeds thatthe invention is useful in a wide variety of applications and may berealized in many different embodiments.

Referring now to FIGS. 1 and 2, an exemplary embodiment of modularwelding equipment according to this invention includes a welding machine10, which is a resistance welder of the spot welding type. The weldingmachine 10 comprises, in general, a base operating machine 12 and atooling module 14 shown in its installed location in the base operatingmachine 12. The base operating machine 12 comprises, in general, amachine frame 16, and at least one welding transformer 17. The toolingmodule 14 comprises a module frame 15 which supports the toolingcomponents required for a particular welding job or product which is tobe run on the machine 12.

The tooling module 14 is installed in the machine 12 as a unit and isremovable as a unit as needed for maintenance, repair or for replacementby another tooling module. The tooling module 14 is adapted for aspecific job only and several different tooling modules may be kept instandby condition which are tooled for particular production jobs whichmay be needed in the future. The base operating machine 12 and thetooling module 14 will be described in greater detail below.

The machine frame 16 comprises a table structure that includes a toolingmodule station at an upper location on the machine frame 16. The toolingmodule station receives the tooling module 14 and, for this purpose,includes a module support guide or rack 19 that enables the toolingmodule to be rolled into and out of the tooling module station. Thetable structure includes front legs 22 with shoe plates 22′, rear legs24, cross beams 26, front to rear longitudinal beams 28 and upperlongitudinal beams 32. A table plate 34 is supported on the upperlongitudinal beams 32. A pair of oppositely disposed rear posts 38extend upwardly from bolt plates 38′ mounted on the longitudinal beams32. A support beam 42 extends transversely of the frame 16 between posts38.

The base operating machine 12 includes the support rack 19 forsupporting the tooling module 14, wherein the support rack 19 comprisesthe table plate 34 and guide means or a roller guide 66. The guide means66 comprises a pair of rails 68 which extend parallel with each other inthe front to rear direction of the machine frame 16. Each rail 68includes a flange plate 72 mounted on the inner side of the rail 68 andeach rail 68 also includes a plurality of rollers or roller bearings 74having a stationary shaft extending through the flange plate 72 and rail68 and secured thereto. The rails 68 are spaced apart laterally so thata bottom plate 76 of the module 14 is supported on the two sets ofrollers 74 and retained in a centered position between the flange plates72. The rails 68 facilitate the removal and installation of the toolingmodule 14 in the base operating machine 12.

The tooling module 14 comprises the module frame 15 which includes thebottom plate 76 with a pair of vertical posts 84 supported thereon inlaterally spaced arrangement. Lower triangular brackets 85 support thevertical posts 84 on the bottom plate 76. The posts 84 together withtriangular brackets 86 support a top plate 88 which is located above thebottom plate 76. The upper tooling is mounted to the top plate 88 andcomprises a pair of weld guns 92. The lower tooling of the module 14comprises a pair of electrodes 98, which are supported on the bottomplate 76.

In order to facilitate the installation and removal of the toolingmodule 14 from the base operating machine 12, a tooling cart or moduletransfer cart 202 is provided as shown in an unlatched location inFIG. 1. The cart 202 is part of the welding equipment described hereinand comprises a rectangular frame 204 which is mounted on a set ofcasters 206. For supporting the tooling module 14 on the cart 202, aguide means or roller guide 266, which comprises rails 268, side platesand roller bearings 274 mounted on the top of the frame 204 in the samemanner as described with reference to the guide means 66 in the supportrack 19 of the welding machine 10. The forward end of the cart 202 isprovided with a pair of alignment pins 208 which extend forwardly fromthe front of the cart frame 204. A pair of alignment sockets 212 aredisposed on the machine frame 16 which are aligned for coaction with thepins 208 when the cart 202 is positioned so that the guide rails 268 onthe cart 202 are in alignment with the guide rails 68 on the supportrack 19. When the cart 202 is positioned so that the pins 208 are fullyinserted into the sockets 212, the tooling module 14 is manually pushedoff the cart 202 from its uninstalled location, onto the support rack 19on the base operating machine 12 to its installed position or location.

A tooling cart latch is used to secure the tooling cart 202 in a latchedlocation with respect to the base operating machine 12. In theillustrated embodiment, two latches are used, each of which includes alatch plate 210 that is mounted on the vertical front frame members ofthe cart 202 and a latch 110 that is attached to the base operatingmachine 12 at one of the two tubular frame members or front legs 22.Thus, when the cart 202 is wheeled up to the machine 12 to transfer atooling module 14 to or from the cart 202, the cart 202 will move intoengagement with the latches 110 to lock the cart 202 in properpositioning against the base operating machine 12 in its latchedlocation. As will be described in further detail below, the latches 110each include a spring loaded first latch member that engages itsassociated latch plate 210 to secure the cart in place. However, it isalso contemplated that the latches 110 could also cooperate directlywith a different portion of the tooling cart 202 such as the framethereof or some other feature besides the latch plates 210.

The two latches 110 can be identical, the only difference being that oneis inverted when being bolted to the base operating machine 12, asindicated in FIG. 2. Accordingly, only one latch 110 will be describedand it will be appreciated that the description applies equally to bothlatches 110.

FIGS. 3 through 7 depict top views of the latch 110 as it would beoriented when mounted on the base operating machine 12 and FIGS. 8 and 9provide perspective and front views, respectively, of the latch 110. Thelatch 110 is attached via its mounting plate 112 that includes two ormore clearance holes 114 through which bolts (not shown) are placed tofasten it to the framework of the base operating machine frame 16. Anyother suitable means could be used to attach the latch 110 to themachine frame 16. Extending generally perpendicularly from the mountingplate 112 is a bracket 116 in the form of a flat plate having an endsection 118 that is bent or angled out of the plane of the remainder ofthe bracket 116. This provides a guide surface 120 to center the cart202 as it approaches the base operating machine 12 from its unlatchedlocation so that the cart 202 need not be in perfect alignment as it isbrought into contact with the machine 12 into its latched location. Thiscan also help achieve alignment of the pins 208 of the cart 202 with thesockets 212 or can eliminate the need for the alignment pins 208 andsockets 212 altogether.

The bracket 116 includes an aperture or hole 122 at a central locationnear the bend in the bracket 116 that defines the angled end section118. On the side of the bracket 116 opposite the guide surface 120 sideis a spring housing 124 that is welded, threaded, press-fit, orotherwise rigidly attached to the bracket 116 about the hole 122 (i.e.substantially concentric with the hole 122). The spring housing 124 isbasically a hollow component that has a cylindrical shape with a backwall 126 that serves to retain a spring 128 within the housing 124. Thespring 128 is a helical compression spring mounted on a shaft 130 thatextends through the housing 124. The shaft 130 is connected at one endto a handle 132 or knob and at the other end to a cylindrical end pieceor head 134 located within the hole 122 in the bracket 116. It iscontemplated that the shaft 130 and head 134 could be one integralcomponent instead of being separately attached and such arrangements areequivalent. The head 134 has a back surface or shoulder 136 againstwhich the spring 128 presses to force the shaft 130 and head 134outwardly through the hole 122 in the bracket 116. The head 134 alsoincludes an angled bearing surface 138 at its exposed or free end.Extending perpendicularly through the shaft 130 near the knob 132, andbetween the spring housing 124 and the knob 132, is a pin 140 thatextends transversely through a portion of the shaft 130 and engages acam surface 142 at the free end of the spring housing 124. The spring128 operates to bias the head 134 and shaft 130 outwardly of the springhousing 124 in an inboard direction so that the angled bearing surface138 is positioned beyond or inboard of the hole 122 in the bracket 116at an exposed location. The extent of movement of the head 134 and shaft130 in this biased direction is limited by engagement of the pin 140with a detent 144 in the cam surface 142. Thus, the head 134 and shaft130 are spring loaded, with these components being movable against thespring bias by pulling on the knob 132.

As shown in FIGS. 4 and 5, in use, when the cart 202 is moved up to thebase operating machine 12 from its unlatched location to its latchedlocation, the latch plates 210 mounted on the cart 202 engage the angledbearing surfaces 138 of the heads 134 of the latches 110 as the cart 202is advanced toward and eventually into contact with the machine 10. Thiscauses the head 134 and shaft 130 to retract against the bias of thespring 128, as shown in FIG. 4. Once the cart 202 has been moved fullyinto engagement with the machine 12, the latch plate 210 moves past thehead 134, allowing it to spring back to its original position, andthereby latching the cart 202 in place against the machine, as shown inFIG. 5. The tooling module 14 can then be transferred between the cart202 and machine 16.

Referring now to FIG. 6, when the operator is ready to remove the cart202 from the machine 10, the latch 110 is released by pulling the knob132 and turning it 180° so that the angled bearing surface 138 now facesthe opposite direction. As the cart 202 is pulled away from the machine10, the latch plate 210 again engages the angled bearing surface 138,forcing the head 134 and shaft 130 to move outwardly while the cart 202is removed. This is shown in FIG. 7. The knob 132 can then be rotatedback to its original position so that it will be properly positioned forwhenever the cart 202 is again used for transferring another toolingmodule. As will be appreciated, the V-shaped profiled cam surface 142and detent 144 shown in these figures allows the angled bearing surface138 to be maintained in either of the two 180° orientations.

Referring now to FIGS. 10 and 11, there is shown another embodiment 302of the tooling cart in which it includes a safety tooling module latch150 to prevent the tooling module (14 of FIG. 1) from being moved off atooling cart 302 unless and until the tooling cart 302 is properlypositioned at the base operating machine 12. The tooling cart 302 can besimilar to the tooling cart 202 of FIG. 1, except as described below.When the tooling module (not shown) is situated on top of the cart 302,a module latch member such as a locating pin or shot pin 152 is used tolatch it to the cart 302 to prevent the tooling module 14 from rollingoff of the cart 302. The shot pin 152 is dropped down through a hole(not shown) in the tooling module base plate or frame (not shown), andthis shot pin 152 extends longitudinally in a vertical direction into avertically extending passage of a shot pin block 154 on the cart 302where it is latched. Until this pin 152 is unlatched, it cannot beremoved and the tooling module cannot therefore be rolled off the cart302. The shot pin 152 is latched using a cart latch member of thetooling module latch 150 such as a probing rod 156, which extendsforward of the cart 302 and is spring loaded into the position shown inFIG. 10 in a transversely extending passage of the block 154.

The probing rod 156 is mounted on a frame member such as a rectangularupper fork lift tube 304 of the cart 302. In its biased position asshown, the rod 156 extends through a mounting block 158 and into theshot pin block 154 wherein the rod 156 selectively engages an engagementrecess such as a reduced diameter groove 160 of the shot pin 152 whichis shown in FIG. 11. With the probing rod 156 transversely extendingwith respect to and engaging the shot pin 152 in this groove 160, theshot pin 152 cannot then be removed due to the interference orengagement between the probing rod 156 and end portion of the shot pin152.

With reference to FIG. 11, when the cart 202 is brought into engagementwith the welding machine (10 in FIG. 1), the probing rod 156 engages aportion of the machine 10, such as the machine frame 16, and is pushedbackwards against the bias force of a spring 162. The probe rod 156continues moving backwards through the shot pin block 154 until the cart302 is properly in its latched position at the machine 10 (e.g., usingthe tooling cart latch discussed in connection with FIGS. 1-9). At thispoint, a disengagement recess 164 in the probing rod 156 will besubstantially adjacent and aligned with the vertical passage and shotpin 152 in the shot pin block 154 so that there is no longer anyinterference or interengagement of the probing rod 156 with the shot pin152, and the shot pin 152 can therefore be removed to thereby unlatchthe tooling module. As shown in FIG. 11, the probing rod 156 may be anassembly of two separate rods 166, 168 coupled together with a couplingnut 170 and jam nuts 172 on either end thereof to provide a shoulderagainst which the spring 162 locates. Alternatively, however, it iscontemplated that a single rod could be used with an integral annularflange or a circlip fastener or the like to provide a shoulder forcooperating with the spring 162.

Typically, tooling modules are stored on their associated cart 302 whennot in use. Rather than storing them on an entire cart, such that onefull cart (including casters and all) is needed for each tooling module,the cart 302 can be made in two sections, as shown in FIG. 10. An upperportion or section has a framework including laterally opposed forklifttubes 304 for supporting roller guide 366 including its guide rails 368and rollers 374. The upper section also includes a laterally extendingcross-member 306, which connects rear ends of the fork tubes 304, anddownwardly extending tubular legs 308 at each of the four corners of thecart 302. A lower portion or section of the cart 302 includes a cartbase 312 or truck, which has its own framework including laterallyopposed and longitudinally extending forklift tubes 314 andlongitudinally opposed and laterally extending cross-members 316. Thebase 312 also includes fixed casters 318, swivel casters 320, andlevelers 322, as well as locators 324 at each of the four corners. Thelocators 324 are preferably semi-spherical in shape and are aligned withand easily mate with the open ends of the tubular legs 308 of the uppersection so that the upper section normally sits on the cart base 312 andstays in place due to its weight, but can be lifted up off the cart base312. As such, open ends of the tubular legs 308 act as female locatorsfor cooperating with the base locators 324 which fit partially up intothe tubular legs 308. This arrangement permits the tooling module to beleft on the upper cart section so that it can be stored in this manneron the upper section, while the cart base 312 is then available for usewith other tooling modules and upper cart sections (not shown).

Those of ordinary skill in the art of welding machine technologyrecognize that the operation of welding machines is often controlledusing a programmable logic controller (PLC). Each tooling moduleoperates under program control provided by the programmable logiccontroller (PLC), wherein a stored computer program is provided in thePLC corresponding to each different tooling module. When a module isinstalled in the base operating machine, the program for running themodule may be manually selected by the operator by a program selector ina control cabinet of the machine (not shown). In the past, programmingof the PLC has typically been done using ladder logic, with the PLCcontrolling operation of both the welding controller and the varioussolenoid valves used to drive pneumatic cylinders or other actuatorsthat load, manipulate, weld, and unload a part. For each differenttooling module used, a separate set of ladder logic is written andloaded into the PLC. However, for the welding machine 10 of thedisclosed embodiment, an improved operator interface is provided whichpresents the operator with a simplified user interface that permitsprogramming of the necessary sequencing of valves and weld operations toaccomplish the required task for any particular tooling module. Thus,when switching over to a different tooling module, new ladder logic neednot be specifically written for the new tooling module, but rather, justa new sequence of operations using the interface.

As described with respect to the welding machine of the incorporatedU.S. Pat. No. 6,512,195 patent, the PLC can be a Nematron™ PTC5800 andthe HMI can be a Nematron™ 5.7 inch touchscreen, both of which areavailable from Nematron Corporation of Ann Arbor, Mich., USA(www.nematron.com). The HMI touchscreen is used by the machine operatorto input the sequencing of operations for a particular tooling module.An exemplary touchscreen input display is shown in FIG. 12. It isthrough this user interface that the operator can define the propersequencing of valve and welding operations for the tooling unit withouthaving to write direct ladder logic for the PLC.

Any given overall welding cycle (or Auto Cycle) consists of a number ofsequences that can be entered by the operator through the touchscreenuser interface. For example, the welding machine might permit up toeight sequences for a single welding cycle in which case eight of thesesequence definition screens would be filled out by the operator. Thesequence number (1-8) may be displayed at the top, center of thetouchscreen, and on either side of this are previous and next buttons toallow the operator to move forward or backward through the sequences.For each sequence, there are eleven possible command and data entries,with a twelfth entry at the bottom used to specify whether there aremore sequences to enter or whether the operator is done with the weldingcycle definition. The programming of each of these twelve entries is asfollows in accordance with an exemplary method of the present invention:

Step one: Select “Valve On” command (range: 0-7); each numbercorresponds to a solenoid valve on the base machine. This valve couldcontrol a pneumatic cylinder on the tooling module such as a weldcylinder, weld cylinder slide, clamp cylinder, locate cylinder, unloadpart cylinder. Enter 0 if no command is used. The master PLC programwill check that all machine inputs and outputs are okay to start andcontinue machine cycle.

Step Two: Select “Delay Timer” command (range: 0.0 to 3.00 sec.); thistimer is the delay between the “Valve On” above this command and the“Valve On” below this command. Enter 0 if no delay is used.

Step Three: Select “Valve On” command (range: 0-7); each numbercorresponds to a solenoid valve on the base machine. This valve couldcontrol a pneumatic cylinder on the tooling module such as a weldcylinder, weld cylinder slide, clamp cylinder, locate cylinder, unloadpart cylinder. Enter 0 if no command is used.

Step Four: Select “Delay Timer” command (range: 0.0 to 3.00 sec.); thistimer is the delay between the “Valve On” above this command and the“Valve On” below this command. Enter 0 if no delay is used.

Step Five: Select “Input On” and enter input (range: 0-16) that isrequired to be “on” at this point in the sequence. The master PLCprogram will check for this input to go on and off each auto cycle.Enter 0 if input check is not desired at this point in Auto Cycle.

Step Six: Select “Input On” and enter input (range: 0-16) that isrequired to be “on” at this point in the sequence. The master PLCprogram will check for this input to go on and off each auto cycle.Enter 0 if input check is not desired at this point in Auto Cycle.

Step Seven: Select “Weld Such.” and enter the weld schedule number(range: 0-63) that is required for this weld. The master PLC programwill turn on the binary select, weld enable, and initiate weld outputsthat interface with the weld controller. It will also confirm the weldcomplete signal from the weld controller. Enter 0 if no weld is desiredat this point in Auto Cycle.

Step Eight: Select “Valve Off” command (range: 0-7); each numbercorresponds to a solenoid valve on the base machine. This valve couldcontrol a pneumatic cylinder on the tooling module such as a weldcylinder, weld cylinder slide, clamp cylinder, locate cylinder, unloadpart cylinder. Enter 0 if no command is used.

Step Nine: Select “Delay Timer” command (range: 0.0 to 3.00 sec.); thistimer is the delay between the “Valve Off” above this command and the“Valve Off” below this command. Enter 0 if no delay is used.

Step Ten: Select “Valve Off” command (range: 0-7); each numbercorresponds to a solenoid valve on the base machine. This valve couldcontrol a pneumatic cylinder on the tooling module such as a weldcylinder, weld cylinder slide, clamp cylinder, locate cylinder, unloadpart cylinder. Enter 0 if no command is used.

Step Eleven: Select “Delay Timer” command (range: 0.0 to 3.00 sec.);this timer is the delay between the “Valve Off” above this command andthe “Valve Off” below this command. Enter 0 if no delay is used.

Step Twelve: Select “More=1, Done=0”; Enter 1 to choose to have thissequence linked to the next sequence to follow. Enter 0 to choose to“End” the Auto Sequence. The master PLC program will complete the autocycle, counters will display completed part in batch counter, tipcounters, and master counter. Selecting a “Save Seq.” button saveschanges to the master PLC program memory for each sequence.

The programming of the HMI and PLC needed to provide these displayscreens and receive the input and use it to control the welding machinein the desired manner is routine and all within the level of skill inthe art.

It will thus be apparent that there has been provided in accordance withthis invention welding equipment and a welding method that achieve theaims and advantages specified herein. It will, of course, be understoodthat the forgoing description is of preferred exemplary embodiments ofthe invention and that the invention is not limited to the specificembodiments shown. Various changes and modifications will becomeapparent to those skilled in the art. All such changes and modificationsare intended to be within the scope of this invention.

As used in this specification and appended claims, the terms “forexample,” “for instance,” and “such as,” and the verbs “comprising,”“having,” “including,” and their other verb forms, when used inconjunction with a listing of one or more components or other items, areeach to be construed as open-ended, meaning that the listing is not tobe considered as excluding other, additional components or items. Otherterms are to be construed using their broadest reasonable meaning unlessthey are used in a context that requires a different interpretation.

1. Welding equipment, comprising: a welding machine including: a baseoperating machine having a tooling module station; and at least onetooling module sized to be received in said tooling module station andconnectable to said base operating machine to enable welding operationsusing said tooling module under control of said base operating machine;a tooling cart that engages said base operating machine adjacent saidtooling module station such that said tooling module can be transferredbetween said tooling cart and said base operating machine; at least onetooling cart latch that includes a first latch member on said baseoperating machine and a second latch member on said tooling cart,wherein said tooling cart is latched to said base operating machine byengagement of said latch members when said tooling cart is brought intoengagement with said base operating machine at a location adjacent saidtooling module station, whereby said tooling cart latch is used toinhibit relative movement between said tooling cart and said baseoperating machine.
 2. Welding equipment as defined in claim 1, furthercomprising a tooling module latch that includes a module latch member onsaid tooling module and a cart latch member on said tooling cart,wherein said module latch member engages said cart latch member toprevent said tooling module from moving off said tooling cart. 3.Welding equipment as defined in claim 2, wherein said module latchmember comprises a pin having a longitudinal axis and having anengagement recess for cooperation with said cart latch member, andwherein said cart latch member comprises a rod oriented transverselywith respect to said longitudinal axis of said pin, said rod having adisengagement recess and being engaged with said pin in said engagementrecess thereof, said pin being disengageable with respect to said rodwhen said rod is moved such that said disengagement recess of said rodis positioned substantially adjacent said engagement recess of said pin.4. Welding equipment as defined in claim 3, wherein said tooling modulelatch further includes: a block having a substantially verticallyoriented passage therein for accepting one end of said pin and furtherhaving a transversely oriented passage therein for accepting one end ofsaid rod; and a spring positioned between said block and a portion ofsaid rod for biasing said rod towards a position in which saiddisengagement recess is not aligned with said vertically orientedpassage; said rod having an opposite end for contacting a portion ofsaid base operating machine as said tooling cart is brought intoengagement with said base operating machine; wherein, when said toolingcart is latched to said base operating machine by said tooling cartlatch, said rod is displaced against a bias force of said spring toposition said disengagement recess of said rod substantially adjacentsaid vertically oriented passage so as to permit insertion and removalof said pin from said block.
 5. Welding equipment as defined in claim 1,wherein said tooling cart comprises: a reusable lower section includinga base having a first plurality of locators thereon; and a removableupper section including a second plurality of locators for engaging saidfirst plurality of locators of said base.
 6. Welding equipment asdefined in claim 5, wherein said first plurality of locators includessemi-spherical members and wherein said second plurality of locatorsincludes tubular legs.
 7. Welding equipment as defined in claim 1,wherein said base operating machine and said tooling cart each includesa frame having front legs on opposed sides of said frame, wherein saidat least one tooling cart latch comprises two laterally opposed latches,each of which includes (i) said first latch member mounted to one ofsaid front legs of said base operating machine frame and (ii) saidsecond latch member mounted to one of said front legs of said toolingcart frame.
 8. Welding equipment as defined in claim 7, wherein each ofsaid second latch members comprises a latch plate and wherein each ofsaid opposed latches comprises: a bracket having an aperturetherethrough; a spring housing attached to said bracket over saidaperture, said housing extending in a longitudinal directionsubstantially transverse with respect to said bracket and terminating ina free end having a cam surface and a detent, said housing having aspring wall located intermediate said free end and said aperture; ashaft disposed through said aperture of said bracket and through saidhousing, said shaft terminating in a head defining a shoulder, said headhaving an angled bearing surface; a spring circumscribing a portion ofsaid shaft and having one end in contact with said shoulder of saidshaft and having an opposite end in contact with said spring wall ofsaid housing so as to bias said head away from said spring wall andthrough said aperture such that said angled bearing surface is locatedat an exposed location outside of said housing and said aperture; and apin extending substantially transversely through a portion of said shaftand being biased into said detent under a bias force of said spring. 9.Welding equipment as defined in claim 8, wherein said tooling cartengages said base operating machine at a location between said opposedfirst latch members wherein said latch plates of said tooling cartcontact said angled bearing surfaces to displace said shafts against thebias force of said springs as said tooling cart is advanced toward saidbase operating machine whereafter said latch plates are disposed betweensaid shafts and said frame of said base operating machine and retainedtherebetween by said heads of said latches so as to secure said toolingcart in a latched position with respect to said base operating machine.10. Welding equipment as defined in claim 9, wherein said shafts areretractable against the bias force of said springs to permit said latchplates of said tooling cart to clear said heads of said shafts as saidtooling cart is moved away from said welding machine.
 11. Weldingequipment as defined in claim 9, wherein said shafts of said latches areadapted to be rotated 180 degrees so as to present said angled bearingsurfaces toward said latch plates of said tooling cart when said toolingcart is in said latched position, wherein as said tooling cart is movedaway from said welding machine, said latch plates of said tooling cartcontact said angled bearing surfaces of said opposed first latch membersto displace said shafts against the bias force of said springs to permitsaid tooling cart to be disengaged from said base operating machine. 12.A tooling cart latch adapted to be used with a base operating machine ofa welding machine and adapted to secure a welding tooling cart in alatched location with respect to the base operating machine, saidtooling cart latch comprising: a bracket having an aperturetherethrough; a spring housing attached to said bracket over saidaperture, said housing extending in a longitudinal directionsubstantially transverse with respect to said bracket and terminating ina free end having a cam surface and a detent, said housing having aspring wall located intermediate said free end and said aperture; ashaft disposed through said aperture of said bracket and through saidhousing, said shaft terminating in a head defining a shoulder, said headhaving an angled bearing surface; a spring circumscribing a portion ofsaid shaft and having one end in contact with said shoulder of saidshaft and having an opposite end in contact with said spring wall ofsaid housing so as to bias said head away from said spring wall andthrough said aperture such that said angled bearing surface is locatedat an exposed location outside of said housing and said aperture; and apin extending substantially transversely through a portion of said shaftand being biased into said detent under a bias force of said spring. 13.Welding equipment, comprising: a welding machine including: a baseoperating machine having a tooling module station; and at least onetooling module sized to be received in said tooling module station andconnectable to said base operating machine to enable welding operationsusing said tooling module under control of said base operating machine;a tooling cart that engages said base operating machine adjacent saidtooling module station such that said tooling module can be transferredbetween said tooling cart and said base operating machine; at least onetooling cart latch that connects said tooling cart to said baseoperating machine to maintain said tooling cart in a fixed position withrespect to said base operating machine during transfer of said toolingmodule between said tooling cart and said base operating machine; and atleast one tooling module latch that connects said tooling module to saidtooling cart to inhibit shifting of said tooling module duringtransportation of said tooling module on said tooling cart.
 14. Weldingequipment as defined in claim 13, wherein said tooling cart latchcomprises: a bracket having an aperture therethrough; a spring housingattached to said bracket over said aperture, said housing extending in alongitudinal direction substantially transverse with respect to saidbracket and terminating in a free end having a cam surface and a detent,said housing having a spring wall located intermediate said free end andsaid aperture; a shaft disposed through said aperture of said bracketand through said housing, said shaft terminating in a head defining ashoulder, said head having an angled bearing surface; a springcircumscribing a portion of said shaft and having one end in contactwith said shoulder of said shaft and having an opposite end in contactwith said spring wall of said housing so as to bias said head away fromsaid spring wall and through said aperture such that said angled bearingsurface is located at an exposed location outside of said housing andsaid aperture; and a pin extending substantially transversely through aportion of said shaft and being biased into said detent under a biasforce of said spring.
 15. Welding equipment as defined in claim 14,wherein said at least one tooling cart latch comprises a pair of opposedlatches mounted on said base operating machine and wherein said toolingcart engages said base operating machine at a location between saidopposed latches such that said tooling cart contacts said angled bearingsurfaces to displace said shafts against the bias force of said springsas said tooling cart is advanced toward said base operating machinewhereafter portions of said tooling cart are disposed between saidshafts and said base operating machine and retained therebetween by saidheads of said latches so as to secure said tooling cart in a latchedposition with respect to said base operating machine.
 16. Weldingequipment as defined in claim 15, wherein said shafts are retractableagainst the bias force of said springs to permit said latch plates ofsaid tooling cart to clear said heads of said shafts as said toolingcart is moved away from said welding machine.
 17. Welding equipment asdefined in claim 15, wherein said shafts of said latches are adapted tobe rotated 180 degrees so as to present said angled bearing surfacestoward said portions of said tooling cart when said tooling cart is insaid latched position, wherein as said tooling cart is moved away fromsaid welding machine, said tooling cart contacts said angled bearingsurfaces of said opposed first latch members to displace said shaftsagainst the bias force of said springs to permit said tooling cart to bedisengaged from said base operating machine.
 18. Welding equipment asdefined in claim 13, wherein said tooling module latch includes a pinand a rod, said pin having a longitudinal axis and an engagement recess,and said rod being oriented transversely with respect to saidlongitudinal axis of said pin, said rod having a disengagement recessand being engaged with said pin in said engagement recess thereof, saidpin being disengageable with respect to said rod when said rod is movedsuch that said disengagement recess of said rod is positionedsubstantially adjacent said engagement recess of said pin.
 19. Weldingequipment as defined in claim 18, wherein said tooling module latchfurther includes: a block having a substantially vertically orientedpassage therein for accepting one end of said pin and further having atransversely oriented passage therein for accepting one end of said rod;and a spring positioned between said block and a portion of said rod forbiasing said rod towards a position in which said disengagement recessis not aligned with said vertically oriented passage; said rod having anopposite end for contacting a portion of said base operating machine assaid tooling cart is brought into engagement with said base operatingmachine; wherein, when said tooling cart is latched to said baseoperating machine by said tooling cart latch, said rod is displacedagainst a bias force of said spring to position said disengagementrecess of said rod substantially adjacent said vertically orientedpassage so as to permit insertion and removal of said pin from saidblock.